The intentions of the assailant are yet unknown to the police. Australia's Prime Minister Tony Abbot said he thinks the reasons behind the assault may be political.

Earlier media reports said an Islamic shahadah flag could be seen in one of the windows. There were also reports of the assailant demanding a flag of the Islamic State terrorist group. Deputy police commissioner Catherine Burn refused to comment the reports, saying she has no right to disclose details of an ongoing operation. Neither did she comment on the reports saying five hostages have escaped from the cafe.